1. Field of Invention
This invention relates to a hinge, more particularly to a hydraulic hinge by which when attached to a door and a door frame and said door is adapted to be pushed open in a predetermined wide angle, a mere push at that particular position will create a self-closing action.
2. Description of the Related Art
Self-closing door hinges are known in the art. Examples of such door apparatuses are disclosed in U.S. Pat. Nos. 1,644,249 and 2,641,794, the latter introducing a door closing hinge with a helical spring attached to the top of the door in such a direction that the unwinding torque it exerts tends to close the door once the door is opened, and a second hinge attached to the bottom of the door which has a helical spring lighter than the helical spring of the first hinge and wound in a direction reverse to that of the same. The action of two helical springs prevents the door from slamming when it closes. A main disadvantage of this hinge is that two complementary hinges with two different helical spring arrangements are needed. This makes the particular hinge more expensive and the installation of the hinges more troublesome for the user.